If you're in a rut, here's your wake-up call. We rounded up the jaw-dropping-est celebrity hair-color transformations of 2013—plus secrets for stealing the looks.

ANNE HATHAWAY

After: Just three weeks later, Hathaway was back to her trademark brunette. "The dark brown is closer to her natural hair color and is much more flattering," Papanikolas says. To re-create it, ask your colorist for tone-on-tone color—a rich chocolate brown base and darker lowlights. "Then do a gloss that's one to two shades lighter," he says. "The subtle difference makes hair look multidimensional and reflects the most light."